Fire extinguishing device for aeroplanes



Patented Jan. 12, 1932 PATENT OFFICE ROBERT E. TOWNSEND, 3'3 01 BOSTON,MASSACHUSETTS FIRE EXTINGUISHTNG DEVICE FOR AEROPLANES Application filedNovember 28, 1930. Serial No. 498,744.

. n This invention relates to fire extinguishing apparatus andparticularly to such apparatus adapted for use in vehicles such asaircraft, boats or automobiles.

When an accident occurs involving aircraft and other vehicles propelledby internal combustion engines one of the serious causes of loss of lifeand property is the fire hazard due to disruption of the fuel system.This is especially true of high speed vehicles such as-aircraft andcertain types of racing vehicles.

The principal object of the present inven-' tion is to rovide-a means toprevent or extinguisli re immediately upon the occurrence of theaccident.

A further object of the invention is to provide a fire extinguishingapparatus which is automatically rendered operative by the shock ofimpact when the vehicle crashes from the air in the case of aircraft orwhen the vehicle comes into contact with another object.

A further object of the invention is to provi'cle a fireextinguishing-apparatus which is setfin operation by the movement of apen- .'dulum pivoted upon the vehicle, such movement of the-pendulumbeinginduced by the sudden stopping of the vehicle when the accidentoccurs.

A further object of the invention .is to provide a fire extinguishingapparatus which automatically renders the ignition system inoperativeand cuts off the supply of fuel to the engine.

. A further object of the invention is to provide afire extinguishingapparatus which is automatic in operation and which may also be renderedoperative by manually-controlled means.

The particular form of the invention illustrated hereii'iis especiallyadapted tobe installed in aircraft. It will be understood,

however, that the broad principles of the invention cover an apparatuswhich may be adapted to any type of vehicle. A reservoir of suitableproportions is provided which contains a quantity of fire extinguishingfluid under pressure. A system of conduits is connected to the reservoirand has a plurality of branches leading to the points of the enginewherea fire hazard is greatest such as the carburetor, the exhaustmanifold or the oil sump.

Normally the extinguishing fluid is exeluded from the distributingsystem by means of a seal of any desirable form such as a thin diaphra mof metal or other suitable material. hen the aircraft or other vehiclecrashes a pendulum which is normally held immovable relatively to thevehicle is caused to move by reason of its own inertia. The movement ofthe pendulum is transmitted to a pointed ram which punctures the sealpermitting the fluid to enter the distributing systom to prevent orextinguish a fire.

As the fluid from the reservoir is admitted to the distributing system apressure is built up therein. This ressure is utilized to actuate aswitch mec anism which renders the '70 ignition system inoperative.Furthermore, to insure complete safety the supply of fuel to the engineis also cut off during the period that the'fire extinguishing fluid isacting to prevent or extinguish a fire.

In the drawings:

Fig. 1 is a partial view of an aeroplane with its forward compartmentbroken awayto show the installation of a preferred embodiment of theinvention.

Fig. 2 is an enlarged view of the apparatus detached from the aeroplane.

Fig. 3 is a detail view of the automatic fuel supply cut off.

Fig. 4-. is a detail view of. the automatic ignition cut out device.

The apparatus is herein shown installed in the forward compartment of anaeroplane 1 equipped with a standard air-cooled internal combustionengine 2. The apparatus is, however, readily adapted to be installed inany type of. vehicle. A reservoir 3 of fire extinguishing fluid isconveniently situated beneath the main fuel supply tank t contain- Engfuel for the engine. The reservoir 3 may contain any suitable fireextinguishing fluid which is maintained under pressure suflicient toproperly distribute the fluid in case of fire. The fluid preferably isof a character espe- 'cially adapted to extinguish oil or hydrocarbonfires.

The reservoir 3 is secured in osition by means of one or more straps 5 wich extend circumferentiall about the reservoir and are fastened to arigid part of the aeroplane such as the partition 6. The fluid may beintroduced in the reservoir in any desirable way. A connection 7 isherein shown which may be connected to a pump or other pressure devicenot shown. The pump acts to introduce the fluid and build up therequired pressure withing the reservoir 3 which is indicated by a gauge8. A distributing system serves to convey the fluid to various parts ofthe aeroplane where the fire hazard is greatest. The

system consists of a main conduit 9 connected to the reservoircommunicating with a lurality of conduits 10 having outlet points whichmay be provided with nozzles 11. The

outlet points may be located at any desired point where they will be themost effective, such as near the carbureter, the exhaust manifold or theoil sum The conduit 9 terminates in a fluid tig t chamber 12 which issupported on a bracket 13 rigidly mounted on a fixed part of theaeroplane.

The end of the conduit 9 extends into the chamber 12 and is sealedby'means of a thin metal diaphragm 14 which is soldered or -otherwisesecured to the end of the conduit. The seal normally excludes the fluidfrom the conduits 10 leading to the outlet points.

Directly below the seal 14 is slidably' mounted a inted ram 15 with itspointed end normally positioned near the seal. The ram is provided witha stem 16 slidable vertically within and closely fitting an aperture ina guiding member 17 which passes through and has a fluid tight unionwith the lower wall of the chamber 12. The member l7functions to guidethe ram 15 vertically.

The lower end of the ram is provided with an enlarged head 18 having asubstantially spherical bottom face. Directly below and in axialalignment with the ram is a pendulum 19 which is universally pivoted inan arm 20 extending substantially horizontally from the bracket 13. Thelower end of the pendulum is provided with a heavy head portion 21 andalso has an upwardly projecting arm 22 which is provided with asubstantially s herical concave face 23 in which is received t espherical face of the head portion on the ram 15.

The ram 15 is normally held in its downward position by means of aspring 24-bearing at its upper end against a shoulder on the member 17and at its lower end against a 001- lar 25 fixed to the stem 16 of theram. The spring 24 is at all times under tension forcing the head 18into engagement with the concave face 23 of the pendulum. The head 18 byengagement with the upwardly. extending arm 22 of the pendulum preventsmovement protected by the device comes in contact with another bodywhich causes damage thereto an excessive force is brought to bear uponthe pendulum due to its inertia. Such force overcomes the action of thes ring 24 and causes the pendulum to swing a out its pivot. As thependulum swings the concave face 23 acts as a cam upon the head 18 ofthe ram forcing it upwardly until its pointed end pierces the seal 14thereby permitting the extinguishing fluid to flow into the chamber 12from where it passes into the conduits leading to the outlet pointssince the distributing conduits are directly connected with the chamber12 at the point 26. The fluid is thus distributed to the danger pointsand by reason of the pressure withm the reservoir 3 is sprayed over aconsiderable area by the noz- Eles 11 thus preventing or extinguishing aAutomatic means are also provided acting simultaneously with the flow offluid to render the ignition system inoperative by grounding the maincircuit. This is accomplished by means of an especially constructedswitch 27 having a cylinder 28 connected to one of the distributingconduits 10. The cylinder 28 is provided with a piston 29 having a stem30 which is guided in a partition 31 one end against the piston 29 andat its other end against the partition 31.

When an accident occurs and the seal 14 is broken pressure isimmediately built up in the conduits 10. Such ressure is transmitted,therefore, to the plston 29 causing it A to move against the action ofthe spring 36 thus forcing the contact member 32 into engagement withthe member 33 establishing an electrical circuit from the ignitionsystem to ground. In order to insure proper grounding of the circuit aspecial grounding wire 37 may be provided which is electricall connectedto the partition 31 which is in 'rect contact with the contact member32. The wire 37 is connected to the frame of the e e thus completing thecircuit to the groun Other suitable means may be employed however toestablish a positive ground. By grounding the ignition circuit theengine immediately ceases to function.

A pressure-actuated fuel supply cut-ofl' valve 39 is provided whichautomatically interrupts the flow of fuel to the engine from the fuelsupply tank 4. The valve is inserted in the supply pipe 38 which extendsfrom the fuel tank 4 to the carburetor 40 on the engine and has alaterally disposed cylinder 41,

" the outer end of which is connected to one of the distributingconduits 10. The cylinder 41 has a piston 42 slidably mounted thereinhaving a piston rod 43 extending upwardly passing through a packinggland 44 which serves as a guide therefor. The piston 42 is normallyheld at the bottom of the cylinder by means of a compression spring 45which is situated on the piston rod and bears at one end on the piston41 and is seated against the upper end 46 of the cylinder.

At the upper end of the piston rod is attached a gate 47 which closelyfits guidewa s 48 extending into the valve chamber 49. T e gate 47 isnormally held out of the chamber 49 permitting flow of fuel in thesupply pipe 38. When the seal 14 is broken, however, pressure isimmediatly built up in the cylinder 41 which moves the piston 42upwardly against the action of the spring 45 thus forcing the gate 47into the valve chamber where it acts to interrupt the fuel supply duringthe period when the fire extinguishing fluid is flowing thereby greatlyminimizing the danger of serious fire loss.

A manual control is provided which enables the operator to control afire as he sits at the controls. A lever 50 is pivoted upon the bracket13 and has a bifurcated arm 51 embracing the piston rod 16. A flexiblecord 52 is connected to the other end of the lever and extendsdownwardly to a guide eye 53 fixed at a convenient point in the cockpitof the aeroplane. From the guide eye the cord extends upwardly to aconvenient position in the cockpit of the aeroplane. The cord isdesirably provided with a suitable handle 54 by means of which the cordis pulled in case of emergency. When the cord is pulled the ram 15 israised through the action of a lever 51 which engages the collar 25 uponthe stem 16 thereof. The ram is thus caused to puncture a seal 14 toliberate the fluid at the will of the operator in cases Where a firestarts from other causes than a crash or collision with another object.

Having thus described the invention, what is claimed as new, and desiredto be secured by Letters Patent, is:

1. A fire extinguishing apparatus for vehicles propelled by internalcombustion engines comprising a reservoir containing fire extinguishingfluid under pressure, a conduit leading therefrom to a distributingsystem, a seal for said conduit acting normally to prevent flow of thefluid to the distributing system, and inertia-operated means including apendulum mounted for universal movement acting to break said seal uponexcessive im act of the vehicle with another body there y to permit thefluid to flow into the distributing system to prevent or extinguish afire.

2. A fire extinguishing apparatus for vehicles propelled by internalcombustion engines comprising a reservoir of fire extinguishing fluidunder pressure, a conduit leadmg therefrom to a distributing system, athin metallic diaphragm sealing said conduit and acting normally toexclude liquid from said system, a pendulum universally pivoted on thevehicle, means operable by said pendulum to break said seal uponswinging movement of said pendulum in any direction caused by violentimpact of the vehicle with another body thereby permitting flow of fluidin said distributing system to prevent or extinguish a fire and meansacting normally to prevent operative movement of said pendulum.

3. A fire extinguishing apparatus for vehicles propelled by internalcombustion engines comprising a reservoir of fire extinguishing fluidunder pressure, a conduit leading from said reservoir to a distributingsystem, a seal for said conduit acting normally to exclude fluid fromsaid system, a eudulum universally pivoted on the vehicle, acam-actuated ram operable by the movement of the pendulum in anydirection caused by violent impact of the vehicle with another object tobreak said seal thereby permitting the fluid to flow in said system toextinguish or prevent fire and means acting normally to prevent motionof the pendulum.

4. A fire extinguishing apparatus for vehicles propelled by internalcombustion engines comprising a reservoir for fire extinguishing fluidunder pressure, a conduit leading therefrom to a distributing system, aseal for said conduit acting normally to exclude fluid from saiddistributing system, a pendulum pivoted on the vehicle, means operableto break said seal when actuated by movement of said pendulum in anydirection upon violent impact of the vehicle with another object therebypermitting pressure from the reservoir to accumulate in said sys tem andcausing the fluid to flow therein and means operable to render theignition system of the engine inoperative actuated by the pressure thusaccumulated in the distributing conduits.

5. A fire extinguishing apparatus for vehicles propelled by internalcombustion engines, a reservoir of fire extinguishing fluid underpressure, a conduit leading therefrom to a distributing system, a sealfor said conduit acting normally to exclude fluid from said distributinsystem,va pendulum pivoted on the vehic e, means operable to break saidseal actuated by movement of said pendulum in any direction upon violentimpact of the vehicle with another object thereby permitting pressurefrom said reservoir to accumulate in said distributing system andcausing the fluid to flow therein and means operable to interrupt theflow of fuel to the engine actuated by the pressure thus accumulated inthe distributing conduits.

6. A fire extinguishing apparatus for vehicles propelled by internalcombustionengines comprising a reservoir of fire extinguishing fluidunder pressure, a conduit leading therefrom to a distributing system, aseal for saidv conduit acting normally to exclude the fluid from saidsystem, a pendulum pivoted on the vehicle, means operable to break the.seal actuated by movement of the pendulum in any direction caused byviolent impact of the vehicle with another object thereby permittingpressure from the reservoir to accumulate in said system and causing thefluid to flow therein to prevent or extinguish a fire, means in saidsystem actuated by the pressure thus accumulated therein to render theignition system of the engine inoperative and pressure-operated means inthe system operable to cut ofi the supply of fuel to the engine.

7. A fire extinguishing apparatus for vehicles propelled by internalcombustion engines comprising a reservoir of fire extinguishing fluid, aconduit leading therefrom to a distributing system, a thin metallicdiaphragm acting as a seal for said conduit normally to exclude liquidfrom said -sys tem, a pendulum pivoted on the vehicle, a ram, positionedto engage said seal, a cam opera 1e by the swinglng movement of saidpendulum in any direction to causesaid ram to break said seal uponviolent impact of the vehicle with another body thereby permitting flowof fluid in said distributing sys- 1 tem to prevent or extinguish'afire, means acting normally to prevent operative movement of saidpendulum and manual means operable independently of saidinertia-operated means to break said seal.

In testimony whereof, I have signed my name to this specificatio ROBERTE. TOWNSEND, JR.

